Incidence trends of gynecologic cancers in urban shanghai,1972-1999

Objective To explore the time trends of incidence of gynecologic cancers in urban Shanghai during 1972 and 1999. Methods Data on the incidences of ovary, cervix and corpus uteri, uteri not otherwise specified (NOS) cancers were obtained from a population-based cancer registry in Shanghai. Age-specific rates per 100,000 person-years were calculated for eight 3-year periods (1972-1995) and one 4-year period (1996-1999). Rates for each period were age-adjusted to the world standard population by direct method using 5-year age groups. Annul percentage changes (APC) in incidence were estimated by means of a linear regression of the logarithm of the respective rates on calendar, weighted by the number of cases. Results Between 1972-1999, 6,106 ovary cancer, 8,063 cervix uteri cancer, 3,933 corpus uteri cancer and 1,312 uteri NOS cancer patients were registered at the Shanghai Cancer Registry. The overall age-adjusted corpus uteri and ovary cancer incidence rates increased 90.8% and 44.2%, or 3.0% and 2.0% per year, respectively, from 1972-1974 to 1996-1999, while that of cervix uteri and uteri NOS cancer decreased 91.8% and 80.2% or 10.5% and 7.1% per year, respectively. Age-specific rates increased in all age groups for ovary and corpus uteri cancers. The increases were more pronounced at ages 55-64, 65-74 for corpus uteri cancer, whereas the estimated annual increases for ovary cancer were over 1.0% for all age groups. The decreases in cervix uteri rates were considerably more rapid at ages 45-54 and 55-64. However, the incidence rates under age 45 increased since late 1980s. Conclusion The findings from this study indicate that the incidence rates of three gynecologic cancers differ by age and in their time trends, suggesting that environmental factors including lifestyle might play an important role in these changes.